Daniël Boer's Physics Webpage

Research subjects [2017]:

Part of my research focuses on novel gluonic effects at high energies. Gluons are the force carriers of the strong interaction, which is one of the four fundamental forces of Nature. The microscopic theory of the strong interaction is the quantum theory of quarks and gluons, called Quantum Chromodynamics (QCD). Unlike Quantum Electrodynamics (QED, the quantum theory of electrons and photons), QCD is a strongly interacting theory and a highly non-linear theory. As a result, it exhibits phenomena that are absent in QED and that are more akin to those of strongly interacting systems in condensed matter physics. These phenomena of QCD show up in extreme circumstances, such as those in the early universe or in ultra-relativistic collisions between heavy ions and/or protons. Currently I am studying the properties of gluons in such extreme conditions, with emphasis on their collective behavior and on the appropriate theoretical description (in terms of Wilson lines and loops).

Our knowledge of gluons has been instrumental in the discovery of the Higgs boson and that may well be the case again for the discovery of new physics beyond the Standard Model of elementary particles in the future. However, so far we have no experimental indication for such new physics, therefore, theoretical investigations will have to follow general guiding principles such as the degree of symmetry and naturalness of the theory. It turns out to be very hard to find highly symmetric (but non-supersymmetric) theories that naturally, i.e. without fine-tuning, lead to the Standard Model at low energies and satisfy the extremely stringent experimental constraints on any new physics. My aim here is to construct new symmetry breaking mechanisms that can be implement in extensions of the Standard Model in a natural way.

Topic 1: Properties of gluons in extreme conditions

Topic 2: Natural extensions of the Standard Model